fix: resolve lint issues

Author: hrshya

lib/node_modules/@stdlib/math/base/assert/is-negative-zerof/benchmark/benchmark.js

@@ -30,6 +30,7 @@ var isNegativeZerof = require( './../lib' );
 // MAIN //
 
 bench( pkg, function benchmark( b ) {
+	var opts;
 	var x;
 	var y;
 	var i;

lib/node_modules/@stdlib/math/base/assert/is-negative-zerof/benchmark/benchmark.native.js

@@ -39,6 +39,7 @@ var opts = {
 // MAIN //
 
 bench( pkg+'::native', opts, function benchmark( b ) {
+	var opts;
 	var x;
 	var y;
 	var i;